01st  Congress,  I  HOUSE  OF  REPRESENTATIVES.    {  Ex.  Doc 
1st  Session,    f  \  No.  40. 


LARCHMOXT  HARBOR,  NEW  YORK. 


LETTER 


FROM 


THE  SECRETARY  OF  WAR, 


TRANSMITTING 


Reports  upon  the  survey  and  preliminary  examination  of  Larch  mo  nt 

Harbor,  New  York. 


December  U,  1889. — Referred  to  the  Committee  on  Rivers  and  Harbors  and  ordered 

to  be  printed. 


War  Department, 
Washington  City,  December  5,  1889. 
The  Secretory  of  War  has  the  honor  to  transmit  to  the  House  of 
Representatives,  in  compliance  with  the;  requirements  of  the  river  and 
harbor  act  of  August  11, 1888,  a  copy  of  the  report  of  Col.  D.  C.  Hous- 
ton, Corps  of  Engineers,  upon  the  survey  of  Larchinoiit  Harbor,  New 
York,  together  with  a  copy  of  his  report  upon  the  preliminary  examina- 
tion of  the  same. 

Redfield  Proctor, 

Secretary  of  War. 
The  Speaker  of  the  House  of  Representatives. 


Office  of  the  Chief  of  Engineers, 

United  States  Army, 
Washington,  D.  C,  December  4,  1889. 
Sir  :  I  have  the  honor  to  submit  the  inclosed  copy  of  the  report  upon 
the  survey  of  Larchmont  Harbor,  New  York,  dated  November  20,1889, 
made  under  the  direction  of  Col.  D.  C.  Houston,  Corps  of  Engineers,  to 
comply  with  the  requirements  of  the  river  and  harbor  act  of  August  11, 
1888,  and  accompanying  map. 

A  copy  of  the  report  upon  the  preliminary  examination  of  the  harbor 
dated  November  28,  1888,  is  also  herewith/ 

The  project  for  improvement  contemplates  the  removal  to  the  plane 
of  15  feet  below  mean  low  water  of  portions  of  Umbrella  Rock  and  Huron 
Rock,  which  obstruct  the  entrance  to  the  harbor.    The  amount  of  niate- 
31.  Ex.  26  — 1 


2  LAKCHMONT  HARBOR,  NEW  YORK. 

rial  to  be  removed  is  given  at  3,665  cubic  yards,  at  an  estimated  edst  of 
$126,600. 

Very  respectfully,  your  obedient  servant, 

Thos.  Lincoln  Casey, 

Brig.  Gen.,  Chief  of  Engineers. 

Hon.  Eedfield  Proctor, 

Secretary  of  War. 


preliminary  examination  of  larchmont  harbor,  new  york. 

Engineer  Office,  United  States  Army, 

New  York,  November  28,  1888. 

Sir  :  I  have  the  honor  to  submit  the  following  report  on  a  prelimi- 
nary examination  of  Larchmont  Harbor,  ]New  York,  made  in  pursuance 
of  the  river  and  harbor  act  of  August  11,  1888,  and  directed  in  letter 
from  the  Chief  of  Engineers,  dated  August  28, 1888. 

The  accompanying  report  of  Lieut.  James  C.  Sanford,  Corps  of  Engi- 
neers, gives  a  detailed  description  of  the  harbor  and  other  information. 

This  harbor  is  located  on  the  north  shore  of  Long  Island  Sound, 
about  20  miles  from  New  York  City.  At  the  entrance  to  the  harbor 
are  two  rocks  which  are  dangerous  to  navigation.  The  cost  of  remov- 
ing these  rocks  to  a  depth  of  15  feet  at  mean  low  water,  is  estimated 
approximately  as  follows : 

Removal  of  Umbrella  Rock,  2,500  cubic  yards,  at  $25  $62,' 500 

Removal  of  Huron  Rock,  225  cubic  yards,  at  $25   5, 625 

Contingencies   9, 875 

Total   78, 000 

This  harbor  is  principally  used  by  vessels  belonging  to  the  Larch- 
mont Yacht  Club,  one  of  the  largest  organizations  of  the  kind  in  this 
country.  In  May,  1888,  the  yachts  enrolled  on  the  club's  list  included 
25  steamers  with  a  total  tonnage  of  1,754  tons,  the  largest  measuring 
568  tons j  26  schooners  with  a  total  tonnage  of  1,491  tons;  70  sloops 
with  a  total  tonnage  of  1,672  tons,  and  55  smaller  boats. 

Since  then,  from  twenty  to  twenty-five  new  vessels  have  been  added, 
ranging  from  20  to  300  tons,  making  the  total  number  about  two  hun- 
dred. The  total  value  of  these  vessels  is  estimated  at  from  $3,500,000 
to  $4,000,000.  The  harbor  is  also  largely  used  by  vessels  belonging 
to  other  clubs,  and  to  a  small  extent  by  commercial  vessels. 

In  view  of  the  value  of  the  property  to  be  benefited  and  the  impor- 
tance to  the  country  of  the  yachting  industry,  I  am  of  opinion  that 
the  harbor  is  worthy  of  improvement. 

In  the  construction  and  navigation  of  yachts,  a  large  number  of  per- 
sons are  employed,  improvements  in  ship  building  are  encouraged,  sea- 
men are  trained  in  their  duties  and  the  naval  power  of  the  country  is 
thus  increased. 

No  general  survey  of  the  harbor  is  needed,  as  the  Coast  Survey 
charts  are  very  complete,  but  a  detailed  survey  of  the  rocks  is  nece 
sary  to  ascertain  the  exact  amount  of  material  to  be  removed.  For 
such  a  survey  the  sum  of  $600  is  estimated. 

Very  respectfully,  your  obedient  servant, 

D.  C.  Houston, 
Lieut.  Col.  of  Engineers. 

The  Chief  of  Engineers,  U.  S.  A. 

AVE* 


LARCHMONT  1IARBOK,  NEW  YORK. 


3 


report  of  lieutenant  james  c.  sanford,  corps  of  engineers. 

Engineer  Office,  United  States  Army, 

New  York,  October  19,  1888. 
Sir  :  In  accordance  with  your  instructions  I  made  a  preliminary  examination  of 
Larchmont  Harbor,  New  York,  on  the  19th  ultimo,  and  have  the  honor  to  make  the 
following  report : 

description  of  harbor. 

Larchmont  Harbor,  known  on  the  Coast  Survey  charts  of  Long  Island  Sound  as 
Delancey  Cove,  is  a  bay  indenting  the  north  shore  of  Long  Island  Sound  about  6  miles 
west  of  the  boundary  line  between  the  States  of  New  York  and  Connecticut.  It  is 
nearly  rectangular  in  shape,  and  is  about  five-eighths  of  a  mile  long  (north  aud  south) 
by  a  half  mile  wide  (east  and  west).  The  headland  on  the  west  side  of  the  entrance 
projects  about  one-fourth  of  a  mile  further  to  the  south  than  that  on  the  east  side  (Long 
Beach  Point).  The  depth  varies  from  0  to  18  feet  at  mean  low  water,  though  the  lat- 
ter depth  exists  only  at  the  mouth  of  the  harbor.  The  area  within  the  12-foot  curve 
is  about  13  acres,  and  that  within  the  6-foot  curve  about  68  acres.  The  mouth  of  the 
harbor  is  obstructed  by  two  rocks  :  Umbrella  Rock,  with  a  depth  of  4  feet  over  it  at 
mean  low  water  and  an  area  within  the  15-foot  curve  of  about  1,350  square  yards  ; 
aud  Huron  Rock  (not  shown  on  the  chart),  with  9  feet  depth  at  mean  low  water  and 
an  area  within  the  ™5-foot  curve  of  about 225  square  yards.  Umbrella  Rockis  about 
800  feet  from  the  west  side  of  the  entrance,  and  Huron  Rock  about  the  same  distance 
from  the  east  side,  both  rocks  being  near  the  line  joining  the  headlands.  An  exten- 
sive reef,  with  outlying  shoal  spots  known  as  the  Hen  and  Chickens,  with  its  highest 
point  3  feet  above  mean  low  water  and  having  an  area  within  the  16-foot  curve  of 
about  75  acres,  lies  about  1,200  feet  directly  south  of  the  mouth  of  the  harbor,  and 
prevents  vessels  from  entering  the  harbor  by  a  direct  course.  Umbrella  Rock  lies 
almost  in  the  center  of  the  channel  by  which  vessels  passing  to  the  west  of  the  Hen 
and  Chickens  enter  the  harbor,  while  Huron  Rock  occupies  a  similar  position  in  the 
east  channel.  Several  vessels  have  struck  Umbrella  Rock  during  the  past  season, 
one  being  considerably  injured,  and  one  vessel  ran  on  Huron  Rock  (the  existence  of 
the  rock  was  not  known  until  this  time)  and  could  not  be  gotten  off  until  the  next 
high  tide,  sustaining  severe  injuries.  On  account  of  the  danger  of  swinging  against 
them,  these  rocks  considerably  reduce  the  anchorage  room  near  the  mouth  of  the  har- 
bor, where  steamers  and  schooners  of  deep  draught  have  to  anchor.  The  harbor  is 
often  overcrowded,  and  the  matter  of  anchorage  room  is  an  important  one. 

present  commerce. 

Larchmont  is  a  suburban  village,  having  a  population  of  about  2,000  in  summer  and 
300  in  winter,  and  is  growing  rapidly.  It  was  founded  and  developed  by  a  land  as- 
sociation known  as  the  Larchmont  Manor  Company.  No  business,  except  hotel  keep- 
ing, is  allowed  to  be  carried  on  in  the  place,  and  the  harbor  is  little  used  for  com- 
merce. The  only  cargoes  brought  into  the  harbor  during  the  past  year  were,  as  far 
as  I  could  learn,  4  schooner  loads  of  building  materials.  It  is,  however,  largely  used 
by  the  vessels  belonging  to  the  Larchmont  Yacht  Club,  one  of  the  largest  and  most 
rapidly  growing  organizations  of  this  kind  in  the  country.  In  May,  1888,  the  club 
had  a  membership  of  504,  and  the  yachts  enrolled  on  the  club's  list  included  25  steam- 
ers, total  tonnage  1,754  tons  ;  26  schooners,  total  tonnage  1,491  tons;  70  sloops,  total 
tonnage  1,672  tons;  and  55  smaller  boats,  tonnage  not  given,  making  a  total  of  176 
vessels,  with  a  total  tonnage  of  4,917  tons,  exclusive  of  the  55  smaller  boats.  The  club 
list  issued  in  May,  188^,  shows  the  condition  of  the  club  at  that  time.  Since  then  the 
membership  has  been  increased  to  597,  and  from  20  to  25  new  vessels,  ranging  from  20 
to  300  tons,  and  having  a  larger  average  tonnage  than  the  vessels  on  the  May  list, 
have  been  added.  The  total  value  of  the  vessels  belonging  to  the  club  is  estimated, 
from  the  known  values  of  several  of  the  vessels,  at  from  $3,500,000  to  $4,000,000. 

A  large  number  of  the  residents  of  Larchmont  are  members  of  the  club  and  yacht 
owners.  Their  yachts  are  usually  anchored  in  the  harbor  during  the  summer  season 
(May  1  to  October  15).  The  other  yachts  belonging  to  the  club  use  the  harbor  for  a 
considerable  part  of  the  season.  In  addition,  a  great  many  yachts  belonging  to  other 
clubs  use  the  harbor.  Their  number  is  estimated  at  about  one-half  the  number  be- 
longing to  the  Larchmont  Club.  At  the  time  of  my  visit,  September  19,  there  were 
1  steam-yachts,  tonnage  260;  3  schooners,  tonnage  142  ;  19  sloops,  tonnage  could  not 
be  obtained;  1  steam-launch,  2  naphtha-launches,  aud 6 cat-boats  in  the  harbor,  with 
a  total  value  of  $465,000.  On  September  1  (the  day  of  a  regatta),  I  counted  in  the 
harbor  5  steam-yachts,  tonnage  592;  9  schooners,  tonnage  421 ;  42  sloops,  tonnage  of 
3,125;  2  tugs,  1  of  100  tons;  4  steam-launches,  1  of  9  feet  draught ;  3  naphtha-launches 
and  about  20  cat-boats.  The  number  given  above  for  September  19  is  only  about 
half  that  using  the  harbor  daily  in  July  and  August.    On  the  night  of  July  3,  1887, 


4 


LAKCHMONT  HARBOR,  NEW  YORK. 


124  cabin  boats  (exclusive  of  smaller)  anchored  in  the  harbor  in  readiness  for  the  re- 
gatta of  July  4;  and  on  July  3,  1888,  the  number  was  considerably  greater.  At  such 
times  (6  to  10  days  each  season)  the  harbor  is  greatly  overcrowded. 

The  yachts  using  the  harbor  frequently  have  to  enter  it  after  dark,  on  account  of 
being  becalmed,  or  other  reasons.  The  rocks  at  the  entrance  are  then  very  dauger- 
ous.  The  rather  light  construction  of  the  yachts  increases  this  danger,  and  their 
comparatively  great  value  renders  the  wreck  of  one  of  the  more  valuable  ones  a 
serious  loss. 

It  is  said  that  within  the  past  season  from  100  to  200  commercial  vessels  have  used 
the  harbor  for  refuge  from  winds  from  west  to  northeast.  This  is  a  decided  increase 
over  previous  vears,  and  is  due  to  the  harbor  being  better  known  and  its  obstructions 
more  thoroughly  buoyed. 

PROSPECTIVE  COMMERCE. 

The  increase  in  the  club's  membership  and  in  the  number  of  yachts  belonging  to  it 
has  been  very  rapid.  This  increase  will  probably  continue.  The  proportional  in- 
crease in  tonnage  has  been  still  greater,  and  it  is  expected  that  mosfc  of  the  largest 
yachts  on  the  North  Atlantic  coast  will  soon  be  on  the  club's  list.  The  finest  yacht 
club-house  in  the  country,  it  is  said,  has  been  erected  here  during  the  past  year,  at  a 
cost  of  over  .$100,000,  and  grounds  covering  several  acres  and  having  a  large  water 
front  have  been  bought  and  finely  improved  by  the  club.  These  added  attractions 
have  largely  increased  the  use  of  the  harbor  by  yachts  during  the  past  season,  and  a 
continued  increase  may  be  looked  for.  A  ship-yard  and  marine  railway  for  the  re- 
pair of  yachts  and  other  vessels  is  to  be  established  on  the  west  side  of  the  harbor. 
It  is  thought  that  the  harbor  would  be  considerably  used  as  a  harbor  of  refuge  by 
coasting  vessels  if  the  obstructions  at  its  mouth  were  removed.  The  improvement 
of  the  harbor  would  increase  its  use  by  the  large  yachting  fleet  of  Long  Island  Sound 
and  New  York  Harbor,  and  would  relieve  the  anchorage  ground  of  commercial  har- 
bors, where  the  anchoring  of  yachts  often  seriously  interferes  with  commerce.  New 
Rochelle  Harbor,  City  Island  Roads,  and  parts  of  New  York  Bay  are  much  obstructed 
in  this  way,  and  collisions  often  result  from  it. 

DESIRED  IMPROVEMENT. 

The  removal  of  Huron  Rock  to  15  feet  at  mean  low  water,  and  of  Umbrella  Rock 
preferably  to  15  feet,  though  its  removal  to  12  feet  would  give  substantial  relief,  as 
there  were  on  the  list  of  last  May  only  six  vessels  belonging  to  the  club  drawing  12 
feet  or  over,  is  desired. 

To  remove  Huron  Rock  to  15  feet  would  require  the  removal  approximately  of  225 
cubic  yards  of  rock  measured  in  place,  which,  at  $25  per  cubic  yard,  would  cost  $5,025. 

To  remove  Umbrella  Rock  to  15  feet  would  require  approximately  the  removal  of 
2,500  cubic  yards  of  rock,  which,  at  §25  per  cubic  yard,  would  cost  $62,500. 

Adding  $9,875  (about  15  per  cent  )  for  engineering  and  contingencies,  would  make 
a  total  of  $78,000. 

If  Umbrella  Rock  were  removed  to  12  feet  the  cost  of  its  removal  would  be  reduced 
about  one-half,  and  the  total  cost  of  the  improvement  would  be  about  $42,500. 

The  rock  taken  out  can  be  deposited  in  the  upper  part  of  the  harbor,  where  it  is  de- 
sired to  form  a  breakwater. 

Before  a  close  estimate  could  be  made,  a  careful  survey  would  be  necessary.  I 
should  estimate  its  cost  at  $(500. 

I  am  indebted  to  Messrs.  G.  C.  W.  Lowrey,  E.  L.  Bushe,  and  others,  of  the  Larch- 
mout  Yacht  Club,  for  information  and  facilities  for  making  the  examination. 
Very  respectfully,  your  obedient  servant, 

James  C.  Sanford, 

J-irst  Lieut,  of  Engineers. 

Col.  D.  C.  Houston, 

Corps  of  Engineers,  U.  S.  A. 


survey  of  larciimont  harbor,  new  york. 

Engineer  Office,  United  States  Army, 

Neio  York,  November  26,  1889. 
General  :  I  Lave  the  honor  to  pubmit  the  following  report  on  survey 
of  Larch  m  on  t  Harbor,  Long  Island  Sound,  New  York,  made  iu  pursuance 
of  the  river  and  harbor  act  of  August  11,  1888. 

I  would  refer  to  my  preliminary  report,  dated  November  28,  1888,  for 
information  as  to  the  amount  of  commerce  and  navigation  to  be  bene- 


LARCHMONT  HARBOR,  NEW  YORK.  5 

fited  by  tlie  improvement  of  this  harbor.  The  entrance  to  t lie  harbor 
is  obstructed  by  two  rocks,  shown  on  the  accompanying  tracing,  known 
as  Umbrella  and  Huron  rocks.  When  the  preliminary  examination 
was  made  it  was  understood  to  be  the  desire  of  those  interested  in  the 
harbor  to  have  these  rocks  removed,  and  a  detailed  survey  was  made  in 
August-September,  1889,  by  Mr.  Henry  X.  Babcock,  assistant  engineer, 
for  the  purpose  of  making  an  accurate  estimate.  I  transmit  his  report, 
which  includes  a  survey  of  other  obstructions  and  an  alternate  project 
for  breakwaters.  This  latter  does  not  at  present  meet  the  approval  of 
those  interested,  but  is  submitted  for  consideration. 

The  quantity  of  rock  to  be  removed  above  the  plane  of  15  feet  below 
mean  low  water  is — for  Umbrella  Rock,  3,329  cubic  yards  ;  for  Huron 
Rock,  336  cubic  yards;  total,  3,(5(35  cubic  yards.  The  estimated  cost  of 
removing  this  amount,  including  contingent  expenses,  is  $12(>,0>()0. 

The  rock  removed  should  be  deposited  on  the  northerly  end  of  Hen 
and  Chickens  Reef,  in  depth  of  14  or  15  feet,  to  form  a  breakwater  or 
beacon  to  clearly  mark  the  location  of  the  reef  and  the  entrance  to 
Larchmont  Harbor. 

Very  respectfully,  your  obedient  servant, 

D.  O.  Houston, 

Colonel  of  Engineers. 

The  Chief  of  Engineers,  U.  S.  A. 


report  of  mr.  henry  n.  babcock,  assistant  engineer. 

Engineer  Office  United  States  Army, 

New  York,  November  21,  1889. 
Colonel  :  I  have  the  honor  to  submit  the  following  report  upon  a  survey  of  Larch- 
mont Harbor,  l#e\v  York,  made  under  your  direction  in  August-September,  1889. 

GENERAL  DESCRIPTION  OF  HARBOR  AND  STATEMENT  OF  PRESENT  AND  PROSPECTIVE 

COMMERCE. 

These  are  given  in  sufficient  detail  and  accuracy  in  your  report  on  the  preliminary 
examination  of  Larchmont  Harbor  (with  Lieutenant  Sanford's  report  as  inclosure) 
dated  November  28,  1888  (see  Letters  Sent— examinations  and  surveys,  pages  204-210). 
The  name  of  the  harbor  is  changed  from  Delancy  Cove  to  Larchmont  Harbor  on  the 
last  Coast  Survey  chart.  No  material  changes  have  taken  place  in  present  or  pros- 
pective commerce  since  the  date  of  that  report. 

SURVEY  AND  MAP. 

In  your  report  upon  the  preliminary  examination  you  stated  that  no  general  sur- 
vey of  the  harbor  was  needed,  as  the  Coast  Survey  chart  was  very  complete,  but  a 
letailed  survey  of  the  rocks  was  necessary  to  ascertain  the  exact  amount  of  material 
to  be  removed.  However,  part  of  the  time  the  water  was  too  rough  to  work  on  the 
rocks,  and  during  that  time  a  partial  survey  of  the  harbor  was  made  in  order  to  show 
the  relation  of  the  rocks  to  the  channels  and  anchorage  ground. 

Umbrella  Rock  was  surveyed  by  driving  four  stakes  around  it  aud  stretching  lines 
across,  taking  soundings  at  5-foot  intervals.  One  of  these  stakes  was  run  down  by 
a  schooner  soon  after  setting,  and  was  replaced.  After  the  work  of  sounding  was 
nearly  finished  sea- weed  collected  on  the  linos  to  such  an  extent  that  they  could  not 
be  stretched  tight,  and  the  rest  of  the  rock  was  covered  with  soundings  located  by 
transits  on  shore. 

Huron  Rock  was  also  surveyed  by  angles  taken  to  each  sounding,  as  the  bottom 
thriv  was  too  hard  to  drive  stakes. 

Besides,  there  are  two  ledges  inside  the  harbor  which  were  surveyed,  as  verbally 
directed  by  you.  Soundings  on  these  ledges  were  also  located  by  intersecting 
angles.  I  could  not  find  any  local  name  applied  to  these  ledges,  so  have  designated 
them  on  the  map  as  North  Ledge  aud  South  Ledge ;  each  is  marked  by  two  spindles, 
oue  near  the  upper  and  one  near  the  lower  end. 

Mean  low-water  plane  was  determined  by  leveling  to  connect  the  tide-gauge  with 
the  bench-mark  at  New  Rochelle  Harbor. 


6 


LAKCHMONT  HARBOR,   NEW  YORK. 


The  general  map  of  the  harbor  is  platted  to  a  scale  of  200  feet  to  the  inch,  and  de 
tailed  maps  of  the  rocks  on  the  same  sheet  to  a  scale  of  20  feet  to  the  inch. 

DETAILED  DESCRIPTION  OF  ROCKS. 

Umbrella  Rock  is  about  800  feet  southeast  from  Umbrella  Point,  from  which  it  is 
separated  by  a  channel  over  16  feet  deep  quite  up  to  the  shore,  with  bottom  of  soft 
mud.  The  rock  is  entirely  surrounded  by  mud  so  soft  that  in  places  it  is  difficult  to 
tell  whether  the  sounding  passes  through  mud  or  not  before  reaching  the  rock.  Um- 
brella Rock  has  two  summits,  one  wit  h  a  least  depth  of  3.1  feet,  the  other  with  least 
depth  of  3.9  feet,  and  having  a  gap  about  10  feet  deep  between  them.  The  surface 
of  the  rock  is  quite  ragged.    The  least  bottom  depth  around  tne  rock  is  15  feet. 

Following  are  the  areas  of  contours  3  feet  apart  ou  this  rock  and  the  volume  of 
rock  in  place  above  such  contours  : 


Area  of. 

Volume  above. 

Square  yards. 

209 
800 
1,  394 
1,997 

Cubic  yards. 

55 
550 
1,(557 
3,329 

Showing  that  the  average  depth  of  rock  is  above  the  12-foot  curve  3.6  feet,  above 
the  15-foot  curve  5.0  feet. 

Huron  Rock  is  about  900  feet  southwest  from  Flagler's  Point,  to  which  it  is  con- 
nected by  a  gradually  sloping  bottom  with  maximum  depth  of  15  feet,  the  bottom 
being  hard  sand  with  many  out- croppiugs  of  rock,  probably  bowlders. 

The  channel  between  the  rock  and  sbore  is  safe  only  for  light-draugbt  vessels. 
Huron  Rock  is  apparently  a  ledge,  with  least  depth  of  9.8  feet,  while  the  least  depth 
of  the  surrounding  bottom  is  15  feet. 

Following  are  the  areas  of  contours  3  feet  apart,  with  the  volumes  of  rock  in  place 
above  each : 


Area  of. 

Volume  above. 

9-foot  contour  

Square  yards. 

0 
148 
495 

Cubic  yards. 

0 

42 

336 

Showing  that  the  average  depth  of  rock  is  above  the  12-foot  curve  1.2  feet,  above 
the  15-foot  curve  2.0  feet. 

North  Ledge  lies  near  the  west  side  of  the  harbor,  about  1,700  feet  north  of 
Umbrella  Rock:  it  is  separated  from  the  west  shore  by  a  channel  of  10  feet  depth 
(except  at  the  north  end,  where  the  depth  is  9  feet),  with  muddy  bottom,  but  this 
channel  is  very  little  used.  The  rock  is  continuous,  but  has  three  crests  rising  above 
low- water  mark,  with  elevations-|-0.7,-|-01.0,-f2.4,  and  depths  of  4  feet  or  over  be- 
tween.   The  rock  is  quite  ragged  and  irregular. 

Following  are  the  areas  of  certaiu  contours  and  volume  of  rock  in  place  above 
each: 


Area  of. 

Volume  above. 

Square  yards. 

74 

1,  304 

2,  602 

Cubic  ya  rds. 

22 
1,  080 
3  024 

Showing  that  the  average  depth  of  rock  is  above  the  6-foot  curve  2.5  feet ;  above 
the  9-foot  curve  3.5  feet. 

South  Ledge  also  lies  near  the  west  side  of  and  near  the  mouth  of  the  harbor  ;  be, 
tween  it  and  the  west  shore  there  is  a  channel  of  LI  tcet  depth,  with  soft  mud  bottom- 
but  the  channel  is  out  of  the  way  and  but  little  used.  The  rock  is  in  two  parts 
separated  by  a  channel  10  feet  deep  and  about  25  feet  wide.  The  north  part  rises  to 
4.1  feet  above  low  water  and  the  south  part  to  1.0  foot  above. 


LARCHMONT  HARBOR,   NEW  YORK. 


7 


Following  are  the  areas  of  certain  contours  for  both  parts  of  this  ledge  together, 
with  volumes  of  rock  iu  place  above  those  contours: 


Area  of. 

Volume  above. 

Square  yards. 

151 
791 
1,  205 
1,  553 

Cubic  yards. 

53 
851) 
1,864 
2,  773 

Showing  that  the  average  depth  of  rock  is  above  the  G-foot  curve  3.2  feet;  above 
the  9-foot  curve  4.G  feet ;  above  the  11-foot  curve  5.3  feet. 

DESIRED  IMPROVEMENT. 

At  the  time  of  the  survey  I  spoke  with  several  members  of  tho  Larchmont  Yacht 
Club,  who  are  the  parties  chiefly  interested  ;  what  they  wished  was  the  removal  of 
Umbrella  and  Huron  rocks.  They  would  also  like  to  have  the  North  Ledge  removed, 
but  did*  not  think  they  would  ask  the  United  Stales  to  undertake  that  now.  At  some 
subsequent  time  they  said  that  they  meant  to  ask  the  Government  to  build  a  break- 
water off  Flagler's  Point  and  perhaps  another  off  the  m6uth  oft  he  harbor,  to  improve 
their  anchorage-ground.  I  suggested  to  them  that  removiug  rocks  was  expensive 
work,  and  that  if  the  breakwater  could  be  arranged  to  cover  the  rocks,  it  would  not 
be  necessary  to  remove  them.  I  made  rough  estimates  from  the  Coast  Survey  charts 
of  the  probable  cost  of  breakwaters  from  each  side  of  the  mouth  of  the  harbor,  one  to 
extend  to  and  cover  Huron  rock,  the  other  to  extend  to  and  cover  Umbrella  Rock, 
and  the  general  opinion  seemed  to  be  that,  as  the  cost  would  not  (apparently)  exceed 
that  of  removing  the  rocks,  it  would  be  the  better  plan  to  adopt ;  and  they  wished 
an  opportunity  to  consider  it  further  when  the  map  was  platted  and  definite  estimates 
could  be  made.  Tho  members  of  the  club  whom  I  spoke  with  were  chiefly,  Commo- 
dore Lowry,  Vice-Commodore  Allie,  Treasurer  Bushe,  and  Messrs.  Coats  and  Murray 
of  executive  committee.  From  your  recent  letter  from  Commodore  Lowry,  I  under 
stand  that  the  project  for  breakwaters  is  definitely  abandoned,  but,  as  directed  by 
you,  I  submit  herewith  estimates  both  for  removal  of  rocks  aud  for  breakwaters. 

9  ESTIMATES  OP  COST. 

On  account  of  the  exposed  position  of  Umbrella  and  Huron  rocks  I  do  not  think 
it  would  be  safe  to  estimate  the  cost  of  their  removal  at  less  than  $30  per  yard,  with 
15  per  cent,  allowed  for  contingencies ;  though  if  the  work  could  all  be  done  under 
one  contract  it  might  be  accomplished  for  less.  North  and  South  ledges  are  more 
sheltered  and  would  have  to  be  excavated  to  less  depth,  and  a  fair  price  for  them 
would  be  $25  per  yard.  To  remove  Umbrella  Rock  to  12  feet,  while  tho  depth  around 
it  is  15  feet,  would  probably  bo  unsatisfactory,  and  efforts  would  subsequently  be 
made  to  have  it  taken  out  to  15  feet  depth  ;  it  would  be  much  more  economical  to 


take  it  out  to  15  feet  depth  at  first. 

Umbrella  Rock,  removing  to  12  feet  depth,  1,657  cubic  yards  at  $30   $49,  710 

Add  about  15  per  cent,  for  contingencies   7,290 

Total  .   57,000 

Umbrella  Rock,  removing  to  15  feet  depth,  3,329  cubic  yards  at  $30   99,  870 

Add  about  15  per  cent,  for  contingencies   15, 130 

Total   115,000 

Huron  Rock,  removing  to  15  feet  depth,  33G  cubic  yards  at  $30   10,  080 

Add  about  15  per  cent,  for  contingencies   1,520 

Total   11,000 

North  Ledge,  removing  to  9  feet  depth,  3,024  cubic  yards  at  $25   75,  GOO 

Add  about  15  per  cent,  for  contingencies   11,400 

Total   87, 000 

South  Ledge,  removing  to  11  feet  depth,  2,773  cubic  yards  at  $25   G9,  325 

Add  about  15  per  cent,  for  contingencies   10,  375 

Total   79, 700 


8 


LARCHMONT  HARBOR,   NEW  YORK. 


Omitting  North  and  South  ledges,  whose  removal  is  not  asked  for,  the  cost  of  re- 
moving Umbrella  and  Huron  rocks  to  15  feet  depth  would  be  $115,000  +  $11,000= 
$120,600.  Or  of  removing  Huron  to  15  feet  and  Umbrella  to  12  feet,  $57,000  -f  $11,600= 
168,600. 

BREAKWATERS. 

Breakwaters  in  this  position  should  be  about  5  feet  wide  on  top  and  built  to  10  feet 
above  low  water  (2%  feet  above  high  water),  with  side  slopes  of  one  on  one. 

Such  a  breakwater  to  cover  Huron  Rock  would  be  930  feet  long;  the  bottom  is 
very  hard  and  little  or  nothing  need  be  allowed  for  settling.  It  would  contain  2:3,0* '0 
tons  of  riprap. 

Such  a  breakwater  to  cover  Umbrella  Rock  would  be  800  feet  long ;  the  bottom  is 
quite  soft,  and  4  feet  average  should  be  allowed  for  settling.  It  would  contain 
42,000  tons  of  riprap. 

Judging  from  prices  obtained  at  David's  Island  sea-wall,  riprap  ought  to  be  pur- 
chased for  these  breakwaters  at  $1.10  per  ton  ;  the  depth  is  ample  for  any  vessels,  ex- 
cept at  the  shore  ends  and  on  the  top  of  Umbrella  Rock,  and  there  is  a  harbor  close 
at  hand.    It  is  not  probable,  however,  that  such  rates  could  bo  obtained,  and  for 


purposes  of  this  estimate  the  cost  is  placed  at  $1.40  per  ton. 

Cost  of  Huron  Breakwater  would  be  23,000  tons  of  riprap  at  $1.40   $32,200 

Add  about  15  per  cent,  for  contingencies   4,800 

Total   37,000 

Cost  of  Umbrella  Breakwater  would  be  42,000  tons  of  riprap  at  $1.40   58, 800 

Add  about  15  per  cent,  for  contingencies   9,  200 

Total   08,  000 

or  total  costfsr  both  breakwaters  $68,000  +  $:i~,000=$105,000. 


The  clear  opening  between  these  breakwaters  would  be  930  feet,  with  depth  of  over 
15  feet,  or  greater  than  obtains  iu  the  harbor  abovo. 

SUMMARY. 

There  are  certain  advantages  which  the  plan  for  breakwaters  would  have  over  the 
one  for  reraovingthe  rocks,  and  which  I  take  the  liberty  of  suggesting  ;  some  of  them 
you  would  notice  at  once,  others  depend  more  or  less  on  the  nature  and  use  of  this 
particular  harbor,  and  are  apparent  only  on  the  ground  or  upon  consideration  of  the 
map. 

(1)  The  channels  east  of  Huron  Rock  and  west  of  Umbrella  Rock  are  seldom  used  ; 
during  six  days  that  I  was  at  Larchmont  I  saw  many  vessels  enter  and  go  out,  and 
do  not  remember  one  to  have  used  those  channels.  The  channel  between  the  rocks 
is  nearly  as  direct  in  any  case  :  it  is  over  900  feet  wide,  and  would  amply  accommo- 
date all  vessels  using  the  harbor. 

(2)  The  harbor  is  not  secure  enough  in  case  of  easterly  gales;  for  three  days  during 
the  survey  a  strong  northeast  wind  was  blowing  and  vessels  had  to  go  well  up  the 
harbor  into  shoal  water.  The  harbor  is  more  exposed  to  east  and  southeast  galea 
than  to  northeast.  The  fact  that  certain  members  of  the  yacht  club  had  considered 
the  need  of  a  breakwater  shows  that  the  harbor  is  not  always  secure. 

(3)  I  was  told  that  at  some  seasons  of  the  year  quite  a  number  of  oyster  and  lishing 
boats  run  in  there  for  the  night  or  for  shelter  during  storms;  they  would  not  be 
materially  interested  in  having  the  rocks  removed,  but  would  be  in  having  the  safety 
of  the  harbor  improved. 

(4)  These  breakwaters  would  secure  a  shelter  from  storms  of  from  30  to  90  acres 
area,  according  to  direction  of  storms. 

(5)  Besides  the  evident  economy,  as  appears  in  the  estimates,  it  is  impossible  to  tell 
in  advance  what  submarine  rock  removal  will  cost,  if  let  by  contract ;  if  done,  under 
successive  small  appropriations  the  cost  might  be  considerably  above  the  estimate. 
A  proper  price  for  riprap  can  be  much  more  readily  ascertained,  and  if  it  were  pur- 
chased at  a  favorable  time,  and  excavation  stone  from  New  York  City  were  accepted, 
the  price  might  bo  much  lower  than  the  estimated  cost  per  ton. 

Respectfully  submitted. 

Henry  N.  Babcock 
Assistan t  Engineer, 

Col.  D.  C.  Houston, 

Corps  of  Engineers. 


O 


